If you've got a Subaru on back-order, be prepared to wait a little longer.

Because one of the Japanese brand's major global production facilities has been frozen after a suspected fault in a power-steering part was discovered.

The temporary shutdown, which could last as long as two weeks, is expected to cost the company more than $100m (NZD 147,381,500), with the factory in question responsible for producing around 60 per cent of the brand's total global output.

Japanese newspaper Asahi reports that, while the suspect part is used in the brand's Forester, Impreza and XV models, the problem has frozen the entire Gunma production facility since January 16.

The plant is expected to remain closed until at least January 28.

According to Japanese reports, more than 10,000 vehicles have been impacted by the possible defect, all built between late December 2018 and January 16, and Subaru in Japan has told owners to immediately stop driving their cars if a problem with the steering emerges.

"The steering control warning light in the instrument panel lights up, the power steering function stops, and the steering wheel operation becomes heavy (state requiring more force than usual)," a statement reads.